The present invention relates to a method for selecting communication devices for non-vocal patients (who are also referred to in the art as "clients"). In the United States today, there are more than one million people whose speech is severely impaired due to injuries, diseases, or congenital conditions affecting their neuro-motor system. The most common causes of such impairment include cerebral palsy, head injury, and amyotrophic lateral sclerosis. Individuals so afflicted suffer loss or serious impairment of their vocal communication abilities due to the impairment of the muscular control of the speech mechanism, as opposed to damage to the central processing areas of the brain. In such cases, the non-vocal or severely speech impaired patient is often intact cognitivel but presents a general degradation of motor ability and coordination.
As a result of this problem, many communication devices have been developed over the years to maximally exploit the patient's remaining motor abilities in order to provide the patient with an opportunity to communicate. There are approximately 100 communication devices commercially available which are designed to aid a disabled user. These devices use different control modes, numerous control interfaces and a variety of language menus. Because of the variety of such devices, and the many types and degrees of a user's communication impairments, clinicians have experienced major difficulties in optimally choosing a communication system for a particular non-vocal patient. It is extremely difficult for a clinician to maintain an awareness of all available devices and even more difficult to compare such devices in a meaningful manner to fit the needs and abilities of individual patients.
The usual clinical solution to this problem is as follows: A clinician reviews available devices and chooses a few which appear, in the clinician's judgement, to fit the patient's abilities. The patient then tries these systems for a short period of time and based on this trial, a particular device is chosen for the patient. There are typically two steps taken by the clinician in making the choice of a non-vocal communication system. The clinician's first problem is to exclude those devices that cannot be used by the particular patient. Usually, such a decision is based on the patient's physical incapability as, for example, the patient's range of motion as it relates to the extent of the keyboard used in the device. Further, a low cognitive ability on the part of the patient may also require exclusion of some of the more complicated devices. The second step in this process is the clinician's decision as to which of the remaining devices is likely to meet the patient's specific needs best.
As can be readily understood, such a process is highly subjective. Usually, however, the initial process of excluding those devices that cannot be used by a patient works reasonably well since it can often be based on obvious physical comparisons such as identifying keyboards which may be too large for a client's reach or those with keys or switches with too much activation force.
A much more difficult problem for the clinician, however, is the basis for prescribing a particular device for a particular patient's needs once the initial exclusion process has been completed. The resulting trial and error method whereby a potential user is exposed to a number of machines for a short time period often provides only a poor indicator of the patient's long term success or satisfaction with a particular device. The potential user is not generally in a position to make sound judgments about what will be effective in meeting his or her needs, or how he or she will perform with the device over an extended period of time. Judgments about how device features would optimize a patient's use of a particular device are difficult to make because of the number of factors and tradeoffs involved. Moreover, a clinician's experience may not provide a means for making such comparisons, certainly not on an objective basis. For example, a clinician does not necessarily have any intuitive knowledge regarding how different keyboard layouts would change a patient's performance with a particular device. Further, even observations which could be easily made, would be difficult to draw conclusions from in any meaningful and complete manner. For example, the knowledge that a patient has less accuracy in the anterior-posterior direction and some visual impairment at the limit of his range of motion in the medial-lateral direction, cannot be used directly to optimize the prescription of a device.
The presently available methods for choosing communication devices to meet the needs of a particular non-vocal user are subject to many limitations and are basically subjective. Such clinical decision-making does not include a systematic assessment of those of the user's motor abilities which are specifically relevant to the use of a particular device. Further, such decision making as presently practiced does not consider a client's preferences in any exhaustive way. It also assumes that a client's performance over a short period of time will be indicative of his performance over an extended period of time. In other words, available methods do not take into account the learning process. Finally, a clinician cannot possibly consider the entire pool of devices available and therefore runs the risk of overlooking a potentially effective device.
It is therefore a principle object of this invention to provide a method for selecting communication devices for non-vocal patients which is systematic and objective.
It is a further object of this invention to provide a method for selecting communication devices for non-vocal users that is capable of embodying present clinical opinion and knowledge. It is yet another object of this invention to provide such a method which is quantitative and computer assisted for efficiency.
It is yet another object of this invention to provide such a system which is interactive in a manner which will provide a tool to assist clinicians in using their knowledge in order to prescribe effective and meaningful communication devices.
It is also an object of this invention to provide a method which is not device limited, i.e., the method is general enough to accommodate the range of existing devices as well as those yet to be developed. This feature also allows the method to be used to test the effect of changes in device characteristics which affect the fit of the device to the user and the communication rate achieved.
Finally, it is another object of this invention to provide a method that is predictive with respect to actual communication rate and user satisfaction and therefore to the amount of actual device use, and to enable a direct comparison to be made between devices based on scoring predicted performance of the user-device pair.